Mass transit systems serve the public interest in alleviating vehicle overcrowding of streets. Unfortunately, it seems that many commuters would simply rather drive a private car than commute to and from work via mass transit. This is due at least in part to the fact that an individual in a private car remains "in touch" with the outside world through news and information heard over the radio, while a mass transit commuter is relatively isolated. To the extent that mass transit systems can be adapted to provide advantages over commuting by private car, or alleviate presently perceived disadvantages of mass transit commuting, these systems will attract more riders and alleviate overcrowding on public roadways, an overcrowding situation which worsens with increasing population and number of vehicles.
Cellular telephone systems enable motorists to converse by telephone with other motorists or with someone located at a land line telephone. Basically, a cellular telephone network includes a geographical area divided into a number of cells, with each cell having a transmitting and receiving station connected to the land line telephone system. As a motorist with a cellular telephone traverses the geographical area, the cellular telephone within the vehicle communicates with the telephone system via radio signals to the station located in the nearest cell, or to the station located in the cell which provides the strongest signal. As the vehicle exits one cell and enters another, the stations of the adjacently located cells "hand off" the communication in order to ensure that the strongest signals are received and transmitted. Hand off also occurs when one cell senses an overload condition due to a high number of users and transfers one or more of the users to an adjacent cell. In other words, a communication link with a cellular telephone may be handed off even though the telephone itself remains stationary. Occasionally, hand off causes some signals to be lost, resulting in missing syllables in a conversation and necessitating repetition of a word or phrase by the speaker. An article entitled "Advance Mobile Phone Service System Description," published on Oct. 12, 1982, describes a cellular telephone system developed by Bell Telephone Laboratories. This article is expressly incorporated herein by reference in its entirety.
Due to increasing popularity, cellular telephone systems have been adapted to a variety of new uses. For instance, Champion, III et al. U.S. Pat. No. 4,812,843 describes an information system in which a subscriber located in a private car may obtain access to information of interest via a cellular telephone. Unfortunately, this system is only available to individual subscribers, and would not be practical for public use on a mass transit vehicle such as a bus, due in part to the fact that the average commute on such a vehicle is only about 15 minutes duration and most passengers would simply not have enough time or room to move freely to a public telephone mounted onboard. Moreover, the ambient noise level on a commuter vehicle such as a bus is generally too high to permit a coherent telephone conversation between a passenger using a cellular telephone and an individual located at a remote telephone.
Vaello U.S. Pat. No. 4,797,914 discloses a conventional pay telephone equipped with a telephone display that can be programmed from a remote site in order to display messages in a time dependent mode to the user of the telephone booth, or at another display mounted nearby. The system utilizes only land line telephone connections, and therefore it does not address any of the problems that are inherent to cellular telephone systems, such as hand off, which would be critical to error-free transmission of messages via the cellular network.